According to the National Institutes of Health, cervical cancer is the third most common form of cancer in women worldwide, but it is much less common in the U.S. because of the routine use of pap smears. Cervical cancer starts in the lining of the cervix, the passage from the vagina to the uterus. Cervical cancer is a slow-growing tumor that progresses through several stages before an advanced stage with extensive spread and complications.
Stage 0
The earliest form of the cancer is abnormal changes, called dysplasia, limited to the lining of the cervix. This is called carcinoma in-situ or cervical intraepithelial neoplasia, according to the American Cancer Society. This is the stage usually picked up by routine pap smears. There is no lymph-node involvement at this stage.
Stage I
Cervical cancer in stage I has invaded deeper tissues in the cervix but still remains confined to the cervix, without any signs of distant spread or lymph-node involvement. This stage is divided into two sub-stages, according to the American Cancer Society. Stage IA describes cervical cancer that has invaded deeper tissues of the cervix but remains visible only by the use of a microscope. At this stage, there is no sign of distant spread or lymph-node involvement. Stage IB cervical cancer is visible to the eye or visible only to the microscope but has invaded more than 5mm into the cervix or is more than 7mm across.
Stage II
Stage II cervical cancers, according to the National Cancer Institute, have spread beyond the cervix into nearby structures but has not grown to the pelvic wall or to the lower third of the vagina. There are also no signs of lymph-node involvement or distant spread. This stage is again divided into two sub-stages based on extent of spread. According to the American Cancer Society, Stage IIA cervical cancer is cancer that has grown into the upper part of the vagina but not into the tissues surrounding the cervix, called the parametria. Stage IIB cancers have spread into the tissues surrounding the cervix, the parametria, as well as the upper two-thirds of the vagina. Beyond this point, later stages involve vital organs, and complications like urinary obstruction begin. According to the American Cancer Society, survival rates also begin a drastic drop beyond this point.
